Which laboratory finding is associated with multiple sclerosis?
a. Several bands on electrophoresis of cerebrospinal fluid
b. Antibody to thyroglobulin
c. Antibody to acetylcholine receptors
d. Presence of antinuclear antibodies
The correct answer and explanation is:
The correct answer is a. Several bands on electrophoresis of cerebrospinal fluid.
Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system, causing inflammation, demyelination, and neurodegeneration. One of the most significant laboratory findings in MS is the presence of oligoclonal bands in the cerebrospinal fluid (CSF), which are detectable by electrophoresis.
Electrophoresis of CSF is a laboratory technique used to separate proteins in a sample based on their size and charge. In individuals with MS, several oligoclonal bands are often present, which reflect the immune response in the central nervous system. These bands are caused by the abnormal production of immunoglobulins (antibodies) in the CNS, specifically IgG. The presence of these oligoclonal bands in the CSF is a hallmark of MS and supports the diagnosis, especially in combination with clinical symptoms and imaging findings. It is important to note that these bands are not specific to MS alone, as they can also be found in other neurological conditions, such as infections or inflammatory diseases. However, when multiple bands are found in the CSF, it strongly suggests MS.
The other options are less relevant to MS:
- b. Antibody to thyroglobulin is associated with thyroid disease, particularly autoimmune thyroiditis.
- c. Antibody to acetylcholine receptors is a marker for myasthenia gravis, a neuromuscular disorder, not MS.
- d. Presence of antinuclear antibodies is associated with systemic lupus erythematosus (SLE) and other autoimmune diseases but not MS.
The detection of oligoclonal bands remains a critical diagnostic tool, alongside clinical features and MRI findings, in diagnosing multiple sclerosis.